把信号的一种频率转换为另一种频率的电讯装置。
An electronic device that converts one frequency of a radio signal to another.
电讯：天线，微波放大装置等；
托盘式电缆桥架是石油、化工、电力、电视电讯等方面最广泛应用的理想敷设装置。
Tray - cable bridge is the most extensive application of the ideal laying devices to oil, chemicals, electric power, telecommunications and television.
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